Automatic control for the movement of carriages



March 26, 1963 R. A. BRAD LEY AUTOMATIC CONTROL FOR THE MOVEMENT 0F CARRIAGES 2 Sheets-Sheet 1 Filed NOV. 21. 1960 N HH INVENTOR ROBERT A. BRADLEY BY WT ATTORNEYS.

United States Patent Ofitice 3,683,296 AUTOMATIC CONTRGL FUR THE MQ'VEMENT F CARRIAGES Robert Auldom Bradley, 18 Ralston Ave, Toronto, Qntario, Canada Fiied Nov. 21, 1956, Ser. No. 76,494 Claims priority, application Canada Dec. 23, 1959 8 Claims. (Cl. 246-322) This invention relates to electric railway apparatus comprising two carrying and power conducting rails, carriages adapted to run on the rails, and a control system for controlling automatically the movement of carriages along the rails.

Railway apparatus is well known which, by means of electric circuits connected to the rails and to the carriage motors, control the movement of trains of carriages on an electric railway. In some cases such railway apparatus is not fully automatic and requires human operators in the trains. Known apparatus having fully automatic control requires that the railway be divided into blocks, each one of which must be controlled. The relay circuits used in the control of these blocks are often very complex and thus more subject to failure than simple circuits, since there are more parts which can fail. Known apparatus is often not suitable for use with a train of carriages each of which carries its own motor because of the problems which occur when a train is partly on one section and partly on another. Known apparatus requires two rails to support the carriages, which rails may also serve as return conductors at ground potential, and at least one additional rail or conductor which supplies current to the motors. In such systems it is necessary to divide the additional rail into insulated sections to which are attached the control circuits.

The present invention avoids the disadvantages discussed above while providing control of the movement of trains of self-powered carriages on an electric railway. Apparatus according to the invention includes a two-rail track for supporting the carriages and for delivering power to the carriage motors through the carriage wheels. One rail is a continuous conductor connected to one terminal of the power supply for the railway. The second rail is divided into insulated sections or blocks. Uncontrolled blocks alternate with controlled blocks. The uncontrolled blocks are connected directly to the second terminal of the railway supply, which is preferably at ground potential. The controlled sections are connected to the second terminal through certain relays whose action will be discussed below. In each carriage of a train except the front carriage, current enters the carriage motor through one of the wheels driven by the motor, and leaves the motor through a relay which is closed only when the train is moving, and thence to the other wheel driven by the motor. This relay is not present in the front carriage. Instead, part of the current flowing to the front motor is diverted to the winding of a relay which is in series with windings of the aforementioned relays in series with the motors of the following carriages. Thus, when current is flowing to the motor of the front carriage, the front relay closes, causing the relays in the following carriages to close so as to allow current to flow through all the motors of the train. This arrangement is provided so that the rear carriages cannot receive power if the front carriage is on a section of track to which power has been cut off.

Each controlled section of the second rail is connected to the second terminal of the power supply through three normally closed relays in series. One of these relays is opened by manual control, one by the presence of a moving train on the controlled section next in front, and one by the presence of a stopped train on the controlled sec- 3,083,296 Patented Mar. 26, 1963 tion next in front. In addition, a manually controlled normally-open relay may be connected between each controlled section and the second terminal of the power supply.

The present invention is especially advantageous for trains of conveyor carriages because no operator is required on the train. The dual function of the rails as current conductors and supporting rails is an economic advantage. Furthermore, if the second terminal of the power source is at ground potential, the divided rail is also at ground potential except those controlled sections upon which a train is stopped or being slowed to a stop. Thus sparking in relay circuits is for the most part avoided, and insulation problems are not as serious as they would be if neither rail were at ground potential. The rail connected to the first terminal of the power source, or hot rail, is a continuous conductor. In other railway control systems, it is this rail which is divided into blocks or sections. Such systems are subject to insulation and sparking problems and, if they use alternating current powered insulated sections, require a transformer and rectifier for each section, whereas the present system needs only one transformer and rectifier for lengths of track up to the maximum economical distance for power transmission at the voltage supplied to the carriage motors. The use of alternate controlled and uncontrolled sections maintains proper spacing between trains, while the cost of relays and control circuits is half what it would be if each section were controlled. The control circuits connected to the rails are designed so that only one relay opens when a train comes in contact with a controlled section, thus ensuring simple operation and a minimum of parts likely to fail. Even in the event of failure of any part of the automatic system, overriding manual controls are provided to keep the system running as it should. The control circuits built into the carriages allow each carriage to be powered separately through its own wheels, while power is cut off to all carriages if the front motor is not being driven. All relay windings, both in the carriages and attached to the rails, are designed to operate effectively without having to carry full load current, thus avoiding the expense of heavy relay coils.

The invention will be described further with reference to the accompanying drawings, in which:

FIGURE 1 is a plan view of a train having a front carriage coupled to a following carriage and showing a schematic diagram of the relay circuits in the carriages. FIGURE 2 is an end view partially in section of one of the carriages shown in FIGURE 1, and FIGURE 3 is a schematic diagram showing the relay circuits attached to the controlled sections of the second rail.

As shown in FIGURE 1 a train comprises several carriages, for example, the first carriage 1 and the second carriage 2. Each carriage runs on rails Z and ZA and has a body X (FIGURE 2) which is insulated from one or more axles Q upon which the body X is mounted. The axle Q is divided into two sections by insulated coupling U. Wheels L1 and L2 are attached to axle Q and run on the rails Z and ZA. A motor S is suspended on the axle Q in such a manner that it can drive the wheels L1 and L2 and hence propel the carriage along the track. Each carriage may have more than one motor, if desired, but even if no motor is present on an axle, it is essential that the wheels be insulated from wheels on the opposite side of the track, and from the body X.

The electric potential required to drive motor S is applied between rail Z and ground. Rails Z and ZA are insulated from ground by supports P. Individual sections of the rails are bonded as shown at W, the ends of the sections cut at an angle to prevent sparking and relay chatter as the wheels pass from one section to another.

When the motor S is operating, current flows from rail Z through wheel L1, and then through brush and ring T1 to the motor S. In carriage 1, the current is diverted before reaching the motor S, through the winding of relay J. Current leaves the motor via brush and ring T2, then through wheel L2 to rail ZA, and thence to ground. In carriage 2, the current is diverted through relay H, before it reaches brush and ring T2. Relay circuits similar to that in carriage 2 are present in the following carriages of the train.

Rail Z is a continuous electrical conductor, but rail ZA isdivided into a series of sections A, B, A B etc. which are insulated from one another. Each uncontrolled section B, B etc. is permanently grounded, and thus the train will norm-ally run on these sections. Controlled sections A, A etc. are connected to ground through certain relays as described below, and on these sections the train may or may not run, depending on the positions of the relays.

One possible path to ground from rail ZA in section A is through the relays E, F, and D and thence through a low resistance R in parallel with the winding of relay D1 to ground. The low resistance is necessary to insure that part of the current will flow through'the winding of relay D1. Relays E, F, and D are normally closed, which means that a train will normally run on section A. If any one ofrelays E, F, and D is open, however, the train will not run, provided relay K is open. Relay K is normally open, and is closed only :if relay KC is closed. This latter relay is also normally open, but may be closed by closing a switch at a control center if it is desired to have a train run in spite of one of relays D, E, F, being open. Two relays K, KC are used here instead of only one, so that a low current from the control center is sufficient to actuate the relays. Similarly, if it is desired to stop a train on section A in spite of relays D, E, and F being closed, a switchat the control center can close relay MC, which will open relay E. Again two relays MC, E are used here so that a low current at the control center willcontrol relay E. Note that position lights in the control center are connected to relays D, F, and K and corresponding relays connected to the other controlled sections'so that the position of each relay may be known.

If a train is moving on section A and relays E, F and D are closed, part of the current flowing through the relays must flow to ground through relay winding D1, and therefore relay D1 must open. Thus a following train on section A1 will stop, since there is no longer a-low-resistance path from rail ZA to ground.

If a train is stopped on section A, current may still flow to ground through the motor in the front carriage, circuit 2-1, and the winding of relay F1. Due to the presence of a high resistance RH in circuit 21, the current from the rail 2 to the rail'ZA via the coil of relay F the circuit 2 1, and the carriage wheels and motors is too small to drive the motors'of the train, yet is large enough to open relay F1. Thus a following train on section A1 will stop if a train is stopped on section A. Note that relay F1 will not open if there is a moving train on section A; current will prefer the low resistance path through relays D, F, and E; and the small current through circuit 2-1 will not be sufiicient to open relay F1.

Thus it is seen that the presence of a train on section A,

whether stopped or moving, causes a following train on.

A1 to stop. This automatic feature is supplemented by overriding manual control, which can allow a train to move if the automatic relays are open, and prevents a train from moving if the automatic relays are closed. Each section of controlled track A, A1, A2 etc. has circuits similar to those described above.

Section A, A1, etc. and B, B1, etc. must be sufiiciently long so that a train following a stopped train will not collide withv it in the process of slowing to a stop, and so that atrain which is not being powered on a controlled section will stop before reaching a permanently grounded part of rail ZA. A suitable system might have sections B, B1, etc. as long as the longest length of train, with sections A, A1, etc. considerably longer than sections B, B1. Also, after the front carriage of a train has reached an unpowered controlled section A, it is desirable that it should be braked to a halt and should not be powered by those carriages to the rear which are still on section B. Thus electric circuits are built into the carriages to accomplish these desired features, as follows:

The front carriage I is equipped with a relay I as shown. Part of the current flowing through the motor passes through the winding of relay 1, causing current to flow through circuit HI and through the winding of relay H. Thus relay H is closed whenever current is being supplied to drive the motor of the front carriage. Otherwise relay H is open, and current will not flow through the motor of the second carriage.

Thus as soon as the front carriage reaches an unpowered controlled section, relay J opens, causing relay H to open. A circuit HH can be connected to following carriages to open relays similar to relay H, thus stopping current flow to all motors as soon as the front carriage is not powered. Solenoid brakes (not shown) in series with all motors respectively are automatically applied when the power current ceases to flow through each motor. It will be noted that a small amount of current flows through the motor of the front carriage, via circuit 2-1 in section A, when the carriage is stopped. This current, however, is insuflicient to keep relay I closed, hence no current is allowed to flow through the motors of carriages to the rear.

What I claim as my invention is:

1. An electric railway apparatus comprising a two terminal power source for the railway, a track formed by tWo carrying and power conducting rails, the first of said rails being a continuous conductor connected to a first terminal of the power source for the railway, and the second of said rails being divided into alternate controlled and uncontrolled sections, each of said uncontrolled sections being connected to a second terminal of the power source for the railway; a train having a plurality of carriages adapted to run on said tracks, each of said carriages having wheels and one or more motors adapted to drive the carriage by turning the wheels, the wheels on the first rail being insulated from the wheels on the second rail, said motors being in electrical contact with the rails and being supplied with current from the rails, the front carriage of the train carrying normally open contacts of a first electromagnetic relay connected in series with and responsive to flow of current through the motor in the front carriage and being adapted to close when current sui'ficient to drive the front motor is being delivered to said front motor, said contacts being connected in series with a source of current and the operating winding of a second electromagnetic relay in each of the following car riages, said second electromagnetic relay having normally open contacts which are connected between one terminal of the motor in said last-mentioned carriage and the corresponding side of the power supply for said last mentioned motor, said last-mentioned contacts being caused to close by the closing of the contacts of the relay in the front carriage; a control system for controlling movement of said train along said track, said control system comprising, for each controlled section, two control relays each having normally closed contacts and an operating winding said normally closed contacts of said control relays being connected together in series between said last-mentioned controlled section of said second rail and said second terminal of the power source for the railway, the operating winding of the first of said control relays for any one controlled section being connected in series between the said second terminal and the controlled section next in front of the said any one controlled section and being energized by current which is caused to flow by the presence of a moving train on the controlled section next in front of said any one controlled section, the operating winding of the second of said control relays for any one controlled section being connected in series between the said second terminal and the controlled section next in front of the said any one controlled section and being energized by current which is caused to flow by the presence of a stopped train on the controlled section next in front of said any one controlled section.

2. Electric railway apparatus as claimed in claim 1, wherein the said source of current comprises the two power conducting rails and the said power source for the railway.

3. An electric-railway apparatus as claimed in claim 2, having two manually controlled relays for each controlled section, the contacts of the first of said manually con trolled relays being connected in series with the contacts of the said two normally closed relays and being normally closed, and the second of said manually controlled relays being a normally open relay connected between the last mentioned controlled section and the second terminal of the power source for the railway.

4. An electric railway apparatus as claimed in claim 2, in which a low resistance is connected in series with the said normally closed contacts of the control relays.

5. An electric railway apparatus as claimed in claim 4, having two manually controlled relays for each controlled section, the contacts of the first of said manually controlled relays being connected in series with the contacts of the said two normally closed relays and being normally closed, and the second of said manually controlled relays being a norm-ally open relay connected between the last mentioned controlled section and the second terminal of the power source for the railway.

6. An electric railway apparatus as claimed in claim 2, in which the winding of said second control relay is connected in series with a high resistance.

7. An electric railway apparatus as claimed in claim 6, having two manually controlled relays for each controlled section, the contacts of the first of said manually controlled relays being connected in series with the contacts of the said two normally closed relays and being normally closed, and the second of said manually controlled relays being a normally open relay connected between the last mentioned controlled section and the second terminal of the power source for the railway.

8. Electric railway apparatus comprising a two-terminal electric power source, a first carrying and current-conducting rail connected to a first terminal of the power source, a second carrying rail divided into alternate controlled and uncontrolled sections, each uncontrolled section being connected to the second terminal of the power source; a control system comprising for each controlled section of the second rail a first electromagnetic relay having normally closed contacts connected in series with the controlled section, and a second electromagnetic relay having normally closed contacts in series with the contacts of the first relay and with the winding of the second relay of the next-following controlled section and with the second terminal of the power source, the winding of the first relay being connected in series with the second terminal of the power source and with a high resistance and with the nextpreceding controlled section; and a train having a plurality of carriages supported by wheels in contact with the rails, the wheels in contact with the first rail being insulated from the wheels in contact with the second rail, the front carriage carrying an electric motor mechanically connected to a pair of wheels thereby to drive the carriage and in electrical contact with the wheels thereby to draw power from the rails, the front carriage carrying a third electromagnetic relay having normally open contacts and whose winding is connected in series with the motor, each following carriage having a fourth electromagnetic relay having normally open'contacts, and each following carriage having an electric motor mechanically connected to a pair of wheels thereby to drive the lastmentioned carriage and electrically connected to a wheel in contact with one of the rails and electrically connected through contacts of the fourth relay to a wheel in contact with the other of the rails, the winding of the fourth relay being electrically connected to a wheel in contact with one of the rails and being electrically connected through the contact of the third relay to a wheel in contact with the other of the rails.

References Cited in the file of this patent UNITED STATES PATENTS 1,208,060 Weller et a1 Dec. 12, 1916 2,084,879 Weise June 22, 1937 FOREIGN PATENTS 239,426 Germany Oct. 13, 1911 

1. AN ELECTRIC RAILWAY APPARATUS COMPRISING A TWO TERMINAL POWER SOURCE FOR THE RAILWAY, A TRACK FORMED BY TWO CARRYING AND POWER CONDUCTING RAILS, THE FIRST OF SAID RAILS BEING A CONTINUOUS CONDUCTOR CONNECTED TO A FIRST TERMINAL OF THE POWER SOURCE FOR THE RAILWAY, AND THE SECOND OF SAID RAILS BEING DIVIDED INTO ALTERNATE CONTROLLED AND UNCONTROLLED SECTIONS, EACH OF SAID UNCONTROLLED SECTIONS BEING CONNECTED TO A SECOND TERMINAL OF THE POWER SOURCE FOR THE RAILWAY; A TRAIN HAVING A PLURALITY OF CARRIAGES ADAPTED TO RUN ON SAID TRACKS, EACH OF SAID CARRIAGES HAVING WHEELS AND ONE OR MORE MOTORS ADAPTED TO DRIVE THE CARRIAGE BY TURNING THE WHEELS, THE WHEELS ON THE FIRST RAIL BEING INSULATED FROM THE WHEELS ON THE SECOND RAIL, SAID MOTORS BEING IN ELECTRICAL CONTACT WITH THE RAILS AND BEING SUPPLIED WITH CURRENT FROM THE RAILS, THE FRONT CARRIAGE OF THE TRAIN CARRYING NORMALLY OPEN CONTACTS OF A FIRST ELECTROMAGNETIC RELAY CONNECTED IN SERIES WITH AND RESPONSIVE TO FLOW OF CURRENT THROUGH THE MOTOR IN THE FRONT CARRIAGE AND BEING ADAPTED TO CLOSE WHEN CURRENT SUFFICIENT TO DRIVE THE FRONT MOTOR IS BEING DELIVERED TO SAID FRONT MOTOR, SAID CONTACTS BEING CONNECTED IN SERIES WITH A SOURCE OF CURRENT AND THE OPERATING WINDING OF A SECOND ELECTROMAGNETIC RELAY IN EACH OF THE FOLLOWING CARRIAGES, SAID SECOND ELECTROMAGNETIC RELAY HAVING NORMALLY OPEN CONTACTS WHICH ARE CONNECTED BETWEEN ONE TERMINAL OF THE MOTOR IN SAID LAST-MENTIONED CARRIAGE AND THE CORRESPONDING SIDE OF THE POWER SUPPLY FOR SAID LAST MENTIONED MOTOR, SAID LAST-MENTIONED CONTACTS BEING CAUSED TO CLOSE BY THE CLOSING OF THE CONTACTS OF THE RELAY IN THE FRONT CARRIAGE; A CONTROL SYSTEM FOR CONTROLLING MOVEMENT OF SAID TRAIN ALONG SAID TRACK, SAID CONTROL SYSTEM COMPRISING, FOR EACH CONTROLLED SECTION, TWO CONTROL RELAYS EACH HAVING NORMALLY CLOSED CONTACTS AND AN OPERATING WINDING SAID NORMALLY CLOSED CONTACTS OF SAID CONTROL RELAYS BEING CONNECTED TOGETHER IN SERIES BETWEEN SAID LAST-MENTIONED CONTROLLED SECTION OF SAID SECOND RAIL AND SAID SECOND TERMINAL OF THE POWER SOURCE FOR THE RAILWAY, THE OPERATING WINDING OF THE FIRST OF SAID CONTROL RELAYS FOR ANY ONE CONTROLLED SECTION BEING CONNECTED IN SERIES BETWEEN THE SAID SECOND TERMIANL AND THE CONTROLLED SECTION NEXT IN FRONT OF THE SAID ANY ONE CONTROLLED SECTION AND BEING ENERGIZED BY CURRENT WHICH IS CAUSED TO FLOW BY THE PRESENCE OF A MOVING TRAIN ON THE CONTROLLED SECTION NEXT IN FRONT OF SAID ANY ONE CONTROLLED SECTION, THE OPERATING WINDING OF THE SECOND OF SAID CONTROL RELAYS FOR ANY ONE CONTROLLED SECTION BEING CONNECTED IN SERIES BETWEEN THE SAID SECOND TERMINAL AND THE CONTROLLED SECTION NEXT IN FRONT OF THE SAID ANY ONE CONTROLLED SECTION AND BEING ENERGIZED BY CURRENT WHICH IS CAUSED TO FLOW BY THE PRESENCE OF A STOPPED TRAIN ON THE CONTROLLED SECTION NEXT IN FRONT OF SAID ANY ONE CONTROLLED SECTION. 